I took my son swimming when he was 3 months old at my condo pool and we swim at least once a week since then. I submerged him underwater from that age and when he was 14 months he can swim by himself underwater for a few feet. He is now 3 and can swim a few meters taking his head above water to breathe. My older boy, 6 yo can swim all 4 strokes fairly well already. I myself am a good swimmer and for me it's definately am important skill to have.